const btn = document.getElementById('nodeBtn');
btn.addEventListener('click',(e)=>{
    const body = document.body;
    if(e.target.innerHTML==='☀'){
        body.style.backgroundColor = "black";
        body.style.innerHTML = '☽'
    } else {
        
        body.style.backgroundColor = "white";
        body.style.innerHTML = '☀'
    }
})